Patent GB-1210265-A (GB)
Title: Test grading and marking method and apparatus
IPC: G06K17/00
Filed: 1968-02-07
Abstract: 1,210,265. Processing answer sheets. AUTOMATA CORP. 7 Feb, 1968 [7 March, 1967 (2)], No. 6061/68. Heading G4M. General.-Test answer cards of the multiple choice type are sensed several rows in advance of a master card, the test responses being stored for a time interval, to enable comparison of each stored test response with the correspond-. ing correct answer sensed from the master card at the time that the corresponding response area on the test card is at a marking station downstream of the test card sensing station. The marking station is controlled to mark the correct position of a response area whenever an incorrect response has been made, and simultaneously to make an error mark at the edge of the test card adjacent the response area. Circuit.-The test and master cards are each sensed by a group of photo-cells A-E, Fig. 2A, one for each response position. Timing marks at one edge of each of the cards are sensed by a further photo-cell 26, 16. An additional photocell at each sensing station adjusts the supply voltage to the sensing photo-cells in accordance with the background illumination reflected from the cards. The timing pulses from channels 16, 26 are applied to bi-stable circuits 105, 100, Fig. 2c, and the associated logic circuit produces 5 msee. shift pulses, provided the two sets of timing pulses are in approximate synchronism. A wide degree of sync. tolerance is allowed, but if two successive sync. pulses from one channel occur before a pulse from the other channel, alarm bi-stable circuit 123 is set. As each row of response positions on the test card is sensed, it is entered in 3-stage shift registers 30-34, successive rows being stepped along by the shift pulses in synchronism with the scanning of the cards. Gates 40-44 compare the contents of the last stages of registers 30-34 with the row of correct answer responses currently being sensed on the master card, gate 61, Fig. 2B, producing an output only in the event of a correct answer. Gate 60 only produces an output if an answer response is sensed on the test card (gate 35), the answer is correct (inverter 66) and the master card response area was not left blank (gate 45). Gate 60 therefore does not produce an output if a response has been omitted on the test card and a response has been entered in the corresponding area of the master card. Gate 65 is enabled in the event of a wrong answer being detected, but not if a response has been omitted on the test card. Counters 92, 94 total the number of right and wrong answers for each card and print the results on the card at the end of a sensing operation. The number of omitted answers is not recorded. Counters 93, 95 record the total right and wrong answers for a batch of test cards. If a response is omitted from the master card, the corresponding response area on the test card is ignored. Whenever an incorrect or omitted answer on the test card is detected, gate 69 is enabled and transfers the correct answer sensed from the master card to marking station 90. Mechanical.-The test cards are fed from a hopper by claws 634, Fig. 16, on an endless chain 630. The sensing statioin includes fibre optics 659 providing ilulminaton of the card from a single light source 652 and channelling reflected light to individual photo-cells. The marking station includes solenoid actuated markers 696 for printing the correct and error marks on the test card, and printing counter wheels 692. The test cards are subsequently withdrawn by roller 710 which is momentarily stopped for a printing operation. Ejected cards return to the hopper as indicated by the dotted line 20. The master card sensing station, Fig. 18 (not shown) includes a continuously rotating drum to which the master card is attached. Cam switches associated with the drum drive, co-ordinate operation of the printing and test card ejection and cause the master card drum to stop in a load position when the last card of a batch has been sensed. Test card switch S1 is closed when the test card is in the sensing station.